README: updated documentation ready for v.0.40.1 patch version

preparing for 'major' release of v0.40.0

IOx: fixing bug where queued values would not get drained

fixing circular ref bug between IO and IOx, which breaks CJS usage

README: adding another IOx demo link

adding 'nextIO()' to event-stream for pulling a single value from a s…

…tream using a monadic (IO) interface

updating/improving the tests

major breaking changes in v0.30.0 (skipping version 0.28.x and 0.29.x…

… to make the breakage more obvious): reorg to put IO related utils under 'io/' subdir, which affects imports (like 'monio/io/helpers' instead of 'monio/io-helpers'), also added two new IO monad (semigroup) variants: 'AnyIO' and 'AllIO', also added new IO helpers: 'iAnd(..)' and 'iOr(..)' that use these new IO variants, respectively

re-implementing 'match' IO helper to work stand-alone, and 'iif', 'el…

…if', and 'els' IO helpers in terms of 'match' -- shorter and more efficient code

adding 'match', 'maybeFromIO', and 'eitherFromIO' helpers to IO-Helpers